In the construction of a household refrigerator having a freezer compartment and a fresh food compartment and an outer case there is an insulating mullion partition between the two compartments and the partition is constructed in such a manner that there is a mullion bar across the front of the partition and secured to the outer case. The freezer and fresh food compartments are closed by separate access doors which are hingedly attached to the cabinet outer case. For the proper fit of the doors for the freezer and fresh food compartments, it is important that the proper width of the refrigerator cabinet be maintained and that the loads on the doors not produce excessive deflection of the cabinet, and further that the door openings are square and more importantly remain square under normal door loadings. The reason for the proper fit of the doors is so the door sealing gaskets can effectively seal against the cabinet to prevent thermal leakage.
Generally household refrigerators employ a sheet metal outer casing and an inner plastic liner with a foamed-in-place thermal insulation resin interposed between the outer case and the inner liner. The liquid/gas foam is introduced into the space between the outer casing and inner plastic liner and expands throughout the space and then is solidified by curing. Prior to the foaming operation it is necessary to cover all of the holes in the liner and outer metal shell so that the foam material does not pass through these holes and solidify, producing a detrimental and unsightly appearance to the user of the refrigerator.
It is customary that the center hinge for the freezer and fresh food access doors be interchangeable from one side of the refrigerator to the other. These hinges must necessarily be structurally rigid and to accommodate fastening the hinges to the outer metal casing, there must be fastener receiving apertures through the front face of the outer casing and reinforcing metal nut strips in the front face for securing the hinge bracket. With such a structural arrangement it is common practice to cover the apertures with a gas permeable material such as fiberglass which will allow the air to escape from between the outer metal casing and the inner liner during the foaming operation but restrict the flow of the foam therethrough. This practice results in an insulation void cavity adjacent the mullion partition resulting in an air path from the freezer compartment to the front face of the outer metal shell. The cold air from the freezer compartment causes the front face of the refrigerator to be cold and with warm moist room ambient air contacting the cold surface of the refrigerator condensation or "sweating" occurs. In constructing refrigerators it is desirable to have all voids in the insulation filled and this invention relates to a method of constructing a refrigerator cabinet that fills the insulation void cavity in the mullion partition area to minimize sweating.